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Class 8 Maths · Chapter 2 · NCERT (hegp102)

Power Play: common misconceptions

See the tempting mistake students make in Power Play, why it feels right at first glance, and a worked visual example that shows the right idea.

The tempting mistake & worked visual

What does an exponent count?

Wrong

2³ = 6

Why it feels right. I multiplied the base by the exponent.

Right

The exponent counts equal factors.

Worked example

2³
2×2×2
8
The exponent tells you how many copies of 2 to multiply.
  1. Write 2³ as 2 × 2 × 2.
  2. There are three factors and the product is 8.

If your child says… (8 concept checks in this chapter)

As you work through Power Play, listen for these everyday misunderstandings and use the prompt alongside each one.

1. Exponential growth See how to teach this step →

If your child says… “Doubling means adding the same amount each time.”

Ask together
Did the layer count increase by the same amount each time?
What’s true
Each increase equals the current amount.
2. Exponential notation and prime factors See how to teach this step →

If your child says… “Two cubed means two times three.”

Ask together
Are these twos added or multiplied?
What’s true
The exponent counts factors, not additions.
3. Multiplying powers and powers of powers See how to teach this step →

If your child says… “Multiplying powers means multiplying their exponents.”

Ask together
How many factors came from each group?
What’s true
When multiplying powers with the same base, keep that base and add the exponents.
4. Powers with the same exponent See how to teach this step →

If your child says… “Multiply the bases and add the exponents.”

Ask together
How many sixes did the pairing produce?
What’s true
Pairing keeps the original number of repetitions.
5. How Many Combinations See how to teach this step →

If your child says… “Just add the numbers of choices.”

Ask together
Does each top get just one bottom, or both?
What’s true
Each top can pair with either bottom, so count both outfits for each top.
6. The Other Side of Powers See how to teach this step →

If your child says… “A zero exponent makes zero.”

Ask together
What remains when each fraction equals one?
What’s true
Every nonzero base has zero power equal to one.
7. Powers of 10 and scientific notation See how to teach this step →

If your child says… “Any multiplier works in standard form.”

Ask together
Is your multiplier at least one and below ten?
What’s true
An equal value may still need rewriting into standard form.
8. Comparing powers and naming large numbers See how to teach this step →

If your child says… “Only the base matters when comparing powers.”

Ask together
Both bases are ten, so what makes their values different?
What’s true
Both the base and exponent affect a power's value.

Use this chapter three ways